COVID-19 is an illness caused by a novel (new) coronavirus that was identified in December 2019. On March 11, 2020, the World Health Organization declared COVID-19 a pandemic.Human coronaviruses are a large family of viruses. They are common and often cause mild illnesses, such as the common cold. But they can also cause more serious illnesses.COVID-19 is a serious health threat, and the situation is evolving daily. For the most up-to-date information on COVID-19 outbreak in Canada, visit canada.ca/coronavirus.